1. Field of the Invention
This invention relates to a bit synchronizer and, more particularly, to a digitally controlled, light weight, low power bit synchronizer.
2. Description of the Related Art
Telemetry data received for processing inherently picks up unwanted noise, typically called "white noise," during transmission. The data of the telemetry signal must be filtered into a clean signal before various processors can convert the data into useful information. In addition, the telemetry data may be in one of the many standard Inter-Range Institution Group (IRIG) code formats, and may need to be converted into a code format compatible with downstream devices or with recording devices for subsequent processing.
It is desirable to perform the filtering and conversion process as quickly as possible, with a device that is both light and inexpensive. Known bit synchronizers mounted on circuit boards for insertion into telemetry analysis systems typically function with a maximum speed performance of 2-5 Mbit/sec. Many stand-alone bit synchronizers also have a maximum speed in the 2-5 Mbit/sec range. There are, however, a few high priced, large, and heavy bit synchronizers which will perform above 15 Mbit/sec. These units, in addition to being large and heavy, require a great deal of power.
Known bit synchronizers have power consumption requirements upward to about 75 watts, weigh up to 40 pounds, take as much as 128 bits to achieve a lock-on, and require frequent calibration. In addition, previous attempts to digitally control the filters of a bit synchronizer have been only moderately successful.